Photovoltaic systems can operate at any voltage between short-circuit voltage where the voltage is zero and open-circuit voltage where the voltage is at the maximum that can be generated by the photovoltaic system. There is an associated current with each point of voltage operation. In order to maximize the output power of the photovoltaic system, the optimal current and voltage operating points must be located. The operating point where the output power of the photovoltaic system is at its maximum is known as the maximum power point (“MPP”). The voltage and current of the photovoltaic system at the MPP is the maximum power voltage (Vmp) and the maximum power current (Imp), respectively.
In some instances, some MPP tracking methods get stuck tracking local MPPs, which are local maxima on the power-voltage curves. Local MPPs have similar qualities to the true MPP but do not represent the true maximum power of the photovoltaic system. The true MPP is also referred to as the “global MPP” because it is the MPP for the entire I-V curve of the photovoltaic system. In contrast, a local maximum power point is an MPP only for a section of the I-V curve.
Structures and techniques disclosed herein can increase the likelihood that the system tracks the global MPP rather than a local MPP.